Question: Tiffany starts counting at 43, and she counts by threes. If 43 is the 1st number that Tiffany counts. what is the 10th number that she counts?
Answer: What is the first number that she counts? $43$ What is the second number that she counts? $\begin{align*}&43 + 3 \\ &= 46\end{align*}$ What is the third number that she counts? $\begin{align*}&43 + 3 + 3 \\ &= 43 + (2 \times 3) \\ &= 49\end{align*}$ What is the 10th number that she counts? $\begin{align*}&43 + (9\times3) \\ &= 43 + 27 \\ &= 70\end{align*}$